1Pour boiling water over baking chocolate, stir and let cool.
Whisk dry ingredients together in a small bowl, set aside.
2Cream butter and vanilla. Add brown sugar and mix well. Add eggs one a time beating well after each egg. Add dry ingredients and mix well. Blend in sour cream and chocolate mixture. Combine well.
3Pour into greased, wax paper-lined 9x5x3 aluminum loaf pan. Bake at 325 degrees for about 1 hour and 15 minutes. Until toothpick comes out clean.
Cool 10 minutes and turn out onto a serving platter and cool completely and frost with recipe below.
Bring to a boil and boil for 1 minute the following:
1 cup granulated sugar
1/4 cup milk
1/4 cup butter
1 ounce (square) chocolate
Remove from heat after boiled for 1 minute and stir in 1/2 tsp. vanilla